Water is a very important resource for all the living organisms . All the water on the earth makes up hydrosphere . Our earth is the only planet having abundance of water . About 71% of the surface of the earth is covered by water.

Oceans are the large interconnecting water bodies encircling the continents . They contain nearly 97% of world’s total water and the rest of the 3% of the water is available in ponds , lakes , rivers , etc